Simple question: If you have a company, say Johns Tech Company, and you have the domain johnstechcompany.com, is it preferable on your correspondence* to capitalize the words that comprise the domain?
Samples:
Info@johnstechcompany.com
…or…
Info@JohnsTechCompany.com
www.johnstechcompany.com
…or…
www.JohnsTechCompany.com
Public poll to follow…
*Both print and electronic, though the issue that brought this question to mind was print (business cards)
I think there are good readability reasons to capitalize.
And no technical reasons not to capitalize that I know of, I know there are maybe a few old email systems that are case-sensitive, but it’s exceedingly rare.
In email addresses, the individual mail servers decide whether to treat the local-part of the address as case-sensitive or not (the part before the ‘@’). As control-z mentioned, email servers that treat addresses as case-sensitive are very rare. But you should still use all lowercase for the local-part just to avoid any potential issues with some goofy server out there treating ‘info@’ and ‘Info@’ differently.
Domain and hostnames are case-insensitive (the part after the ‘@’). Choose whichever you prefer; I personally prefer all lowercase for consistency with the local-part and so I don’t have to hit the shift key. I’m lazy like that.
I prefer the web address to be lowercase to align with the email addresses. Again, for consistency reasons.
You should never arbitrarily capitalize an email address since it’s up to the convention of the mail server whether it will consider all versions of the address to be the same. It may or may not consider info and INFO the same or different. It’s totally up to their own implementation.
Domain names, on the other hand, don’t care about case. The processing of them must be case insensitive. It’s part of the RFC 1035 standard:
Even though you can have capitals in the domain name, I would prefer not. First, it’s not commonly done so it looks odd. Second, it’s easier to type all the lower case than having the mixed case. Most people won’t know that they can type johnstechcompany or JohnsTechCompany, so they’ll type the mixed case.
I’d say you should only possibly capitalize the domain if you have a CamelCase brand name, and your URL is also your brand name. For example, GoDaddy.com makes sense. You could also capitalize if there would be confusion, like the classic ExpertsExchange.com.
For usernames, I would suggest using other separators besides capitals when making your names. Use [noparse]john.doe@johnstechcompany.com, not JohnDoe@johnstechcompany.com[/noparse]. And never capitalize a single word like “info.”
Also, don’t use the “www” any more than you would include the “http://.” The only way it should be used is if it’s part of the brand. Any decent server will be configured to map xxx.com to [noparse]www.xxx.com[/noparse].